The extinct dire wolf was one of the top predators of the ice age and, in parts of the Americas, may have competed with our ancestors for food, says Will Newton
What are dire wolves?
Not to be confused with the fictional wolves from George R.R. Martin’s epic fantasy series A Song Of Ice And Fire, dire wolves are a real-life, now-extinct species of wolf that lived from the Late Pleistocene (about 125,000 years ago) to the Early Holocene ( around 10,000 years ago).
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Where did dire wolves live?
They were, like many prehistoric canids, native to the Americas and ranged from southern Canada in the north to Chile’s Atacama Desert in the south. This expansive range speaks to dire wolves’ tolerance of a range of different habitats. Based on where their remains have been found, it’s thought they lived on plains, grasslands, arid savannahs, and even forested mountains.
That said, it’s unlikely dire wolves tolerated arctic conditions quite as well as today’s wolves do. This interpretation is based on the fact that most dire wolf fossils are found below 42° latitude (Midwestern US) and south of where ice sheets would have extended to during the Last Glacial Maximum and other particularly cold periods of the Late Pleistocene.
Are dire wolves the ancestors of grey wolves?
It’s often said that dire wolves are the closest ancestors of grey wolves (Canis lupus) and their many subspecies. For a long time, this theory was entertained by palaeontologists and dire wolves and grey wolves were both included under the same genus, Canis.
However, a 2021 study on dire wolf DNA revealed that the two species aren’t close ancestors at all; they’re actually evolutionarily distant cousins that broke away from one another more than 5.5 million years ago. This has prompted palaeontologists to assign the dire wolf its own distinct scientific name, Aenocyon dirus.
As a species, dire wolves are part of a highly divergent lineage that look like today’s wolves not because of close evolutionary ties, but because of a process known as convergent evolution. This is a process whereby animals that aren’t closely related evolve similar features/behaviours in response to living in similar environments and occupying similar niches.
Instead of being the closest ancestors of grey wolves, dire wolves are in fact more closely related to jackals, suggesting they might not be ‘wolves’ at all.
How big were dire wolves?
While they may look a lot like today’s wolves, there are several differences that set dire wolves apart. For starters, dire wolves were a lot larger on average. According to estimates, the average dire wolf was roughly the same size as the largest grey wolves (>68kg).
What did dire wolves look like?
They had larger teeth and stronger jaws too. These have been interpreted as adaptations for hunting the large herbivores that roamed the Americas during the ice age. And unlike today’s wolves, dire wolves may have sported shorter coats of reddish-brown fur.
This difference in colour is a departure from more traditional reconstructions of dire wolves, which pictured them as slightly larger versions of grey wolves, and the evidence for it comes from the aforementioned 2021 study.
As a highly divergent lineage that, one, is more closely related to jackals and, two, lived in more temperate environments, it makes more sense that dire wolves had rusty-looking, weather-appropriate coats than shaggy coats of black and grey fur.
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What did dire wolves eat?
It’s thought, based on stable isotope analyses of their bones, that dire wolves had a particular taste for bison and other ruminants. That said, they’d have probably preyed on many other large, herbivorous mammals too, such as camels, horses, and ground sloths. They may have even preyed on, or scavenged, mastodons and mammoths.
In order to kill such large prey, dire wolves relied on the power of teamwork, much like their distant cousins grey wolves do today. As social animals, dire wolves likely hunted in large, familial packs, led by an alpha pair.
Once they’d brought down their prey, dire wolves would have used their powerful jaws and large, grindstone-like cheek teeth known as carnassials to crack bones and get at the calorie-rich marrow hidden inside.
How deadly were dire wolves?
A study examining the estimated bite forces of living and extinct placental mammals found that, when adjusted for body size, dire wolves came out on top. The larger and more rounded canines of dire wolves also suggest they were better at holding down struggling prey than grey wolves.
Living in the Americas during the ice age, dire wolves faced a lot of competition, not only from other species of wolves, such as the extinct Beringian wolf, but also sabre tooth tigers, such as the infamous Smilodon, and American lions. They may have also faced competition from our ancestors who arrived in the Americas between 20,000 and 15,000 years ago.
Did dire wolves live alongside humans?
While there’s very little evidence of dire wolves interacting with humans, it’s understood they lived in the same areas during the last few thousand years of the Pleistocene and hunted very similar prey.
This means that they may have occasionally clashed and found themselves embroiled in some disputes over carcasses; although based on the fact that dire wolves are now extinct it’s clear who probably won the majority of these bloody bouts.
Around this time (around 14,000 years ago), humans tamed wolves and successfully created the first ever domesticated animal, the domestic dog (Canis familiaris).
These wolves that humans tamed weren’t dire wolves, nor were they grey wolves. Instead, it’s thought domestic dogs are descended from a now-extinct species of wolf that lived during the Late Pleistocene and was genetically distinct from modern wolves.
Why did dire wolves become extinct?
As a species, dire wolves faced extinction 10,000 years ago and at roughly the same time as many other iconic ice age mammals, such as sabretooth tigers, cave lions, woolly rhinos, ground sloths, and Columbian mammoths.
Like many other large, predatory animals that lived during this time, it’s thought dire wolves faced extinction as a result of the disappearance of the large herbivores that they preyed upon. It’s heavily debated what caused the extinction of the large herbivores, but consensus suggests that it was most likely a combination of rapid climate change at the end of the ice age and overhunting by humans.
While dire wolves and other large species of wolves, such as the Beringian wolf, became extinct at the end of the ice age, several other canid species survived. These survivors include grey wolves and coyotes, which are smaller than dire wolves, less carnivorous, and not quite as reliant on big game.
It has also been suggested that grey wolves and coyotes may have survived this extinction event due to their ability to hybridise with other canids, such as the domestic dog. As a highly divergent lineage that broke away from the wolf family tree millions of years beforehand, dire wolves weren’t able to do this.
By hybridising with other canids, grey wolves and coyotes may have acquired traits that made them more resistant to diseases spread by animals migrating from Eurasia into North America during the Late Pleistocene.
Did scientists really bring back dire wolves?
If you’ve kept an eye on the news in recent months, then you may have seen that a biotechnology company known as Colossal Biosciences attempted to ‘resurrect’ the dire wolf from extinction. This is a contentious concept known as ‘de-extinction’ and it involves adding the DNA of an extinct animal to the egg of a living descendant before implanting the developing embryo into a surrogate mother.
On April 7th of this year, Colossal Biosciences claimed they had created “the world’s first successfully de-extinct animal”, revealing three genetically modified wolf pups - two six-month-old males named Romulus and Remus and a two-month-old female named Khaleesi.
To do this, Colossal’s scientists made 20 edits to 14 key genes in grey wolf DNA so that the resulting animals would express traits characteristic of dire wolves - no dire wolf DNA was actually spliced into the grey wolf’s genome.
This is controversial for many reasons, not least the ethical implications associated with ‘resurrecting’ an extinct animal. There’s also debate over whether these gene-edited wolves even look like dire wolves - all three are white and bear more resemblance to the character Ghost from A Song of Ice And Fire than a realistic dire wolf reconstruction based on the study of fossils and ancient DNA.
The lead scientist involved with the dire wolf ‘de-extinction’ project, Beth Shaprio, has since walked back claims that these gene-edited wolves are dire wolves, saying in an interview with New Scientist that, “they’re grey wolves with 20 edits.”
To put it simply: no, scientists have not resurrected dire wolves. Instead, they’ve bred three, genetically modified grey wolves that bear some similarities with dire wolves - although whether these similarities are based in reality or the fictional world created by George R.R. Martin is questionable.
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Top image: Getty